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MR imaging of the abnormal sternoclavicular joint— A pictorial essay
ELSEVIER
REVIEW
MR IMAGING OF THE ABNORMAL STERNOCLAVICULAR JOINTA PICTORIAL ESSAY MITCHELL A. KLEIN, MD, ALBERTA M. SPREITZER, MD, PEDRO A. MIRO, MD, AND GUILLERMO F. CARRERA, MD The sternoclavicular [SC] joint can be affected by a wide variety of pathologic conditions. Imaging is usually needed for diagnosis and staging. Although the use of magnetic resonance (MR] imaging has become indispensable in the evaluation of most joints, MR has received little attention in SC joint evaluation. Recently, however, it has been shown that detailed MR images of the normal SC joint can be obtained. This pictorial essay explores the differential diagnosis of the abnormal SC joint and helps to determine the role of MR imaging in the SC joint imQ Elsevier Science Inc., 1997 aging algorithm. KEY WORDS:
Sternoclavicular joint; Magnetic resonance imaging; Joints; Diseases
INTRODUCTION Pain in the sternoclavicular (SC) joint can stimulate pain in the cervical spine, shoulder, rib cartilage, heart, and pleura (1). Additionally, there are a wide variety of causes of SC joint pain. Since clinical examination is difficult, imaging is important. Due to the location and anatomy of the SC joint, plain films have limited utility. Consequently, CT scanning has been the imaging modality of choice in SC joint evaluation (2). Magnetic resonance (MR) imaging, which From the Departmentof Radiology,FmedtertHospital(M.A.K., P.A.M., G.F.C.), and the Departmentof Physical Medicine and Rehabilitation (A.M.S.), Medical College of Wisconsin, Milwaukee, Wisconsin. Addressreprint requests to Mitchell A. Klein, MD,Department of Radiology,Froedteft Hospital, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226. Received November21, 1995; accepted January 5, 1996. CLINICALIMAGING1997;21:138-143 0 Elsevier Science Inc., 1997 655 Avenue of the Americas, New
York,
NY 10010
has dwarfed CT in the evaluation of most joints, has surprisingly received very little attention in the literature in SC joint evaluation (3). In part this results from difficulty in obtaining good quality MR images of the SC joint. The small SC joint is poorly imaged with the body coil. Surface coil imaging has suffered since both the applied coil and the SC joint move with patient breathing, causing severe artifact. Vascular pulsation and swallowing also cause artifacts. Moreover, many magnets do not have the gradient strength to perform the small field of view, high-resolution imaging needed for the SC joints. The difficulty in imaging, combined with most radiologists’ limited experience with SC joint imaging, and the availability of CT scanning of the SC joint has prevented the emergence of MR imaging of the SC joint. As recently shown, however, detailed images of the normal SC joint can be obtained (4). (Figures 1 and 2). The purpose of this pictorial essay is to illustrate the spectrum of MR findings in abnormal SC joints.
A. SC Joint Neoplasms MR imaging is utilized widely for the evaluation of bone tumors. Both benign and malignant primary tumors as well as metastases can involve the SC joints. In general, primary benign and malignant bone tumors as well as metastases are hyperintense on T2weighted images. Signal intensity is unreliable in differentiating benign from malignant bone tumors. In the evaluation of primary bone tumors, several studies have suggested that MR imaging is superior to CT scanning in defining the extent of intramedullary tumor, in determining muscular and neurovascular invasion, and in evaluating joint invasion (5-7) (Figure 3). These features are especially important to
0899-7071/97/$17.00 PI1 SOf399-7071(96)00040-X
MARCH/APRIL
1997
FIGURE 1. Coronal cryomicrotome of a normal cadaveric SC joint demonstrates normal fibrocartilage [arrows) covering the clavicle and manubrium and a normal interposed disc (arrowhead).
define in patients undergoing limb-sparing procedures. In the evaluation of bone metastases, MR imaging may be more sensitive than bone scanning (5) (Figures 4 and 5).
B. SC Joint Arthritis A wide variety of arthritides can involve the SC joint including septic arthritis, rheumatoid arthritis, anky-
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2. Normal cadaveric SC joint. Axial fat-saturated spoiled gradient-echo MR image [TRITE/flip angle = 67/17/60”) shows a normal disc (arrowhead) and normal fibrocartilage (arrows) covering the clavicle (c) and manubrium (m). Note that the disc and fibrocartilage are the same signal intensity. This feature is consistent with their similar fibrocartilaginous histology. FIGURE
losing spondylitis, psoriasis, Reiter syndrome, gout, osteoarthritis, calcium pyrophosphate deposition disease, polymyalgia rheumatica, rheumatic fever, scleroderma, relapsing polychondritis, Behcet syndrome, and idiopathic self-limited arthritis. Rheumatoid arthritis of the SC joint, present in up
FIGURE 3. A 33-year-old male patient with a primary fibrosarcoma. (A) Tl-weighted (500, 20) (top) spin-echo and T2weighted (3,000, 93) (bottom) fast spin-echo sagittal images demonstrate a medial clavicular mass [urrows) with cortical destruction and soft tissue extension. (B) Tl-weighted (500,20) coronal image demonstrates involvement of the medial right clavicle (arrow) with lack of extension across the sternoclavicular joint into the manubrium. MR imaging is better than CT in the evaluation of joint invasion. Evaluation for tumor extension across joints is important for surgical planning. M, manubrium; C, left clavicle.
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B
51-year-old female with bone metastases from breast cancer. (A) Proton density (1,700, 20) axial image demonstrates focal infiltration of the manubrium (arrow) with normal bone marrow in both clavicles. (B] Fat-suppressed TZ-weighted (4,500, 80) axial fast spinecho image demonstrates that the marrow infiltration is hyperintense (arrow) with extension into the soft tissues anteriorly. The marrow fat in both clavicles suppresses normally, excluding trans-joint’ invasion. (C) Tl-weighted (700, 20) sagittal image demonstrates the expansile mass in the manubrium (short arrow) with cortical destruction and breakthrough and associated soft tissue extension. There is a second focal IO-mm lesion (long arrow) in the medial left clavicle with similar signal characteristics but without the cortical destruction or associated soft tissue mass. FIGURE 4.
to 41% of patients with the disease, causes joint effusion, uniform joint space loss, marginal erosions, pannus formation, and intra-articular disc destruction (1,8). The MR findings in patients with rheumatoid arthritis may be similar to those in patients with psoriasis and septic arthritis (Figure 6). All may demonstrate joint effusions, joint capsule distension, marrow edema, erosions, and unilateral involvement. Septic arthritis of the SC joint is uncommon, representing less than 10% of all cases of septic arthritis (Figure 7) (9). SC joint septic arthritis, associated with intravenous drug abuse, results from hematogenous spread, direct inoculation, or contiguous extension of a pathogen (9, 10). Since SC joint septic arthritis may cause only minor signs and symptoms, the diagnosis must always be considered in patients with unilateral SC joint pain; mediastinitis, superior vena cava syndrome, or septic shock can develop quickly (9). Imaging is important in the early diagnosis of SC joint septic arthritis since percutaneous as-
piration is often unsuccessful (1). The MR imaging findings, combined with the history, allow the radiologist to strongly suggest the diagnosis of septic arthritis. A previous case report of SC joint septic arthritis on MR demonstrated bone marrow edema and inflammation in the surrounding soft tissues (3).
C. SC Joint Surgery Iatrogenic causes of an abnormal SC joint include direct SC joint surgery as well as radical neck dissection, which indirectly involves the SC joint. Patients with postoperative changes in the SC joint may demonstrate findings indistinguishable from arthritis, including joint space narrowing, cortical irregularity, joint hypertrophy, and a joint effusion (Figure 8). Consequently, the relevant surgical history is imperative for accurate diagnosis. Following radical neck dissection for neck cancer the SC joint can become enlarged and look suspicious for tumor recurrence. In patients who have had
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1997
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FIGURE 6. A 66-year-old male with known rheumatoid arthritis, new unilateral sternoclavicular joint pain, and a negative sternoclavicular joint aspiration. Proton density (2,000, 20) axial image of the left sternoclavicular joint demonstrates extensive pannus (black arrows), uniform joint space narrowing, and erosions (white arrow) with focal loss of low signal intensity cortex. M, manubrium; C, left clavicle.
B FIGURE 5. A 38-year-old female with bone metastases from breast cancer. (A) Tl-weighted (500, 11) and (B) T2weighted (2,200, 80) axial images demonstrate a focal lomm lesion (long arrows) in the left medial clavicular head, which is low signal intensity on both sequences. Although usually hyperintense, malignant lesions such as this bone metastases can have low signal intensity on T2-weighted images. No soft tissue mass or joint invasion is seen. This lesion could not be seen on the corresponding CT scan. If only a CT scan had been obtained, the cause of this patient’s SC joint pain would have gone undiscovered. There is a normal tiny amount of contralateral right sternoclavicular joint fluid (short arrow). the SC joint resected secondary to this suspicion, a mass of fibrous tissue surrounding and replacing the joint was found (11). SC joint periarticular fibrosis can develop 18 months after radical neck dissection (11). The abnormalities are thought to result secondary to nerve division at surgery creating altered biomechanical forces on the SC joint as well as denervation of the sensory supply to the joint (11).
D. SC Joint Trauma SC joint dislocations are rare, occurring anteriorly more commonly than posteriorly, in spite of the
stronger anterior SC ligament (12). Injury to the SC joint may result in ligamentous sprain without displacement, SC ligament but not costoclavicular ligament disruption with little deformity, or disruption
FIGURE 7. A 5%year-old male intravenous drug abuser with streptococcal septic arthritis of the right sternoclavicular joint. T2-weighted (2,000, 60) axial image demonstrates a large right sternoclavicular joint effusion (white arrow) with extension into the soft tissues anteriorly (black arrows), as well as cortical destruction [arrowheads) and joint space widening. The appropriate diagnosis can be made from the imaging findings and clinical history. M, manubrium; C, right clavicle.
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A 51-year-old female who underwent sternoclaviculsr joint surgery due to chronic dislocation. TZweighted (4,000,92) fat-suppressed fast spin-echo coronal image demonstrates a moderate sized joint effusion (long arrow), joint space narrowing, cortical irregularity (short arrow), and subjacent bone marrow edema in the right clavicle and manubrium. The patient had no past or present signs or symptoms of arthritis in her other joints. Her sternoclavicular joint was asymptomatic at a s-month follow-up without antibiotic therapy. Postoperative findings in the SC joint can be radiographically indistinguishable from inflammatory or infectious arthritis. M, manubrium; C, right clavicle. FIGURE 8.
of both ligaments with complete dislocation
(13). Posterior dislocation commonly results indirectly from trauma to the posterolateral clavicle (12) (Figure 9). Imaging is usually required for diagnosis. Posterior dislocation is important to diagnose since significant neurovascular injury, tracheal laceration, or pneumothorax can result (1).
FIGURE 9. Proton density (1,500, 22) axial image demonstrates a complete posterior dislocation of the right clavicle (long arrow). Imaging is essential in these cases to rule
out an associated mediastinal injury. The mediastinum is normal in this case. (Short arrow), manubrium.
A 67-year-old male with sternocostoclavicular hyperostosis and bilateral sternoclavicular joint pain. There was increased activity in both sternoclavicular joints on bone scan, which was stable for over 2 years. Proton density (2,000, 20) coronal image demonstrates ossification (black arrow) of the left costoclavicular ligament as well as heavy ossification of the first rib cartilage (white arrow). FIGURE 10.
E. Miscellaneous Conditions Ajjfecting the SC Joint Finally,
joint
miscellaneous
include
processes
the SC hyperostosis
affecting
sternocostoclavicular
(SCCH), Paget’s disease, condensing osteitis, primary and secondary hyperparathyroidism, and osteonecrosis. SCCH causes enlargement of the anterior upper ribs, sternum, and medical clavicles and is associated with adjacent soft tissue ossification (8,14). It is associated with certain skin diseases, such as palmoplantar pustulosis in slightly more than half the cases, and can be associated with peripheral or axial arthritis (14). The average age of onset is 47 years (14). The symptoms persist for many years; histologically nonspecific inflammatory change, fibrosis, and new bone formation are seen (14). Radiographically, the SC joint is involved in only 44% of patients whereas sternocostal involvement occurs in 48% (14). Radiographic findings include ossification of the costoclavicular ligament, fibro-osteitis of the costoclavicular ligament attachment site, and hyperostosis of the medial clavicle, anterior upper ribs, and sternum (14) (Figure 10). Advantages of MRI over CT include improved detection and delineation of abnormalities involving the bone marrow, cartilage, articular disc, extra artic-
MARCH/APRIL
MRI OF THE ABNORMAL
1997
ular soft tissues, and joint space, as well as its multiplanar capabilities, lack of radiation, and improved contrast resolution. Disadvantages of MR include decreased spatial resolution, worse motion artifact, longer examination times, and less sensitivity to cortical erosions and calcification/ossification. In conclusion, MR imaging can delineate the abnormal SC joint, allowing the radiologist to provide a limited differential diagnosis. Further study is needed to determine whether MR imaging will supplant CT as the primary imaging modality in evaluating the SC joint.
REFERENCES Yood RA, Goldenber DL. Sternoclavicular thritis Rheum 1980;23(2):232-239.
joint arthritis. Ar-
Cope R, Riddervold JO, Shore JL, Sistrom CL. Dislocations of the sternoclavieular joint: anatomic basis, etiologies, and radiologic diagnosis. J Orthoped Trauma 1991;5(3):379-384. Shanley DJ, Vassal0 CJ, Buckner AV. Sternoclavicular pyarthrosis demonstrated on bone scan correlation with CT and MRI. Clin Nucl Med 1991;10:786-787. Klein MA, Miro PA, Spreitzer AM, Carrera GF. MR imaging of the normal sternoclavicular joint: spectrum of findings. AJR 1995;165:391-393.
STERNOCLAVICULAR
JOINT
143
5. Frank JA, Ling A, Patonas NJ, et al. Detection of malignant bone tumors: MR imaging vs scintigraphy. AJR 1990;155:10431048. 6. Bloem JL, Falke THM, Taminiau AHM, et al. Magnetic resonance imaging of primary malignant bone tumors. Radiographics 1985;5(6):853-886. 7. Bloem JL, Taminiau AHM, Eulderink F, Hermans J, Pauwels EKJ. Radiologic staging of primary bone sarcoma: MR imaging, scintigraphy, angiography, and CT correlated with pathologic examination. Radiology 1988:169:805-810. 8. Resnick D, Niwayama G. Diagnosis of Bone and Joint Disorders, 2nd ed. Philadelphia: W. B. Saunders, 1988, pp. 6742279. 9. Pollack MS. Staphlococcal mediastinitis due to sternoclavicular pyarthrosis: CT appearance. J Comput Assist Tomogr 1990;14[6):924-927. 10. Klein MA, Winalski CS. Wax MR, Piwnica-Worms DR. MR imaging of septic sacroiliitis. J Comput Assist Tomogr 1991; 15(1):126-132. 11. Lamb CEM. Sternoclavicular joint enlargement following block disection. Br J Surg 1976;63:488-492. 12. Cope R, Riddervold
HO. Posterior dislocation of the sternoclavicular joint: report of 2 cases, with emphasis on radiologic management and early diagnosis. Skeletal Radio1 1988;17: 247-250.
13. Ferrandez
L, Yubero J, Usabiaga J, No L, Martin F. Sternoclavicular dislocation: treatment and complications. Ital J Ortho Trauma 1988;14(3):349-355. 14. Saghafi M, Henderson MJ, Buchanan WW. Sternocostoclavicular hyperostosis. Sem Arthritis Rheum 1993:22(4):215-223.
REVIEW
MR IMAGING OF THE ABNORMAL STERNOCLAVICULAR JOINTA PICTORIAL ESSAY MITCHELL A. KLEIN, MD, ALBERTA M. SPREITZER, MD, PEDRO A. MIRO, MD, AND GUILLERMO F. CARRERA, MD The sternoclavicular [SC] joint can be affected by a wide variety of pathologic conditions. Imaging is usually needed for diagnosis and staging. Although the use of magnetic resonance (MR] imaging has become indispensable in the evaluation of most joints, MR has received little attention in SC joint evaluation. Recently, however, it has been shown that detailed MR images of the normal SC joint can be obtained. This pictorial essay explores the differential diagnosis of the abnormal SC joint and helps to determine the role of MR imaging in the SC joint imQ Elsevier Science Inc., 1997 aging algorithm. KEY WORDS:
Sternoclavicular joint; Magnetic resonance imaging; Joints; Diseases
INTRODUCTION Pain in the sternoclavicular (SC) joint can stimulate pain in the cervical spine, shoulder, rib cartilage, heart, and pleura (1). Additionally, there are a wide variety of causes of SC joint pain. Since clinical examination is difficult, imaging is important. Due to the location and anatomy of the SC joint, plain films have limited utility. Consequently, CT scanning has been the imaging modality of choice in SC joint evaluation (2). Magnetic resonance (MR) imaging, which From the Departmentof Radiology,FmedtertHospital(M.A.K., P.A.M., G.F.C.), and the Departmentof Physical Medicine and Rehabilitation (A.M.S.), Medical College of Wisconsin, Milwaukee, Wisconsin. Addressreprint requests to Mitchell A. Klein, MD,Department of Radiology,Froedteft Hospital, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226. Received November21, 1995; accepted January 5, 1996. CLINICALIMAGING1997;21:138-143 0 Elsevier Science Inc., 1997 655 Avenue of the Americas, New
York,
NY 10010
has dwarfed CT in the evaluation of most joints, has surprisingly received very little attention in the literature in SC joint evaluation (3). In part this results from difficulty in obtaining good quality MR images of the SC joint. The small SC joint is poorly imaged with the body coil. Surface coil imaging has suffered since both the applied coil and the SC joint move with patient breathing, causing severe artifact. Vascular pulsation and swallowing also cause artifacts. Moreover, many magnets do not have the gradient strength to perform the small field of view, high-resolution imaging needed for the SC joints. The difficulty in imaging, combined with most radiologists’ limited experience with SC joint imaging, and the availability of CT scanning of the SC joint has prevented the emergence of MR imaging of the SC joint. As recently shown, however, detailed images of the normal SC joint can be obtained (4). (Figures 1 and 2). The purpose of this pictorial essay is to illustrate the spectrum of MR findings in abnormal SC joints.
A. SC Joint Neoplasms MR imaging is utilized widely for the evaluation of bone tumors. Both benign and malignant primary tumors as well as metastases can involve the SC joints. In general, primary benign and malignant bone tumors as well as metastases are hyperintense on T2weighted images. Signal intensity is unreliable in differentiating benign from malignant bone tumors. In the evaluation of primary bone tumors, several studies have suggested that MR imaging is superior to CT scanning in defining the extent of intramedullary tumor, in determining muscular and neurovascular invasion, and in evaluating joint invasion (5-7) (Figure 3). These features are especially important to
0899-7071/97/$17.00 PI1 SOf399-7071(96)00040-X
MARCH/APRIL
1997
FIGURE 1. Coronal cryomicrotome of a normal cadaveric SC joint demonstrates normal fibrocartilage [arrows) covering the clavicle and manubrium and a normal interposed disc (arrowhead).
define in patients undergoing limb-sparing procedures. In the evaluation of bone metastases, MR imaging may be more sensitive than bone scanning (5) (Figures 4 and 5).
B. SC Joint Arthritis A wide variety of arthritides can involve the SC joint including septic arthritis, rheumatoid arthritis, anky-
MRI OF THE ABNORMAL
STERNOCLAVICULAR
JOINT
139
2. Normal cadaveric SC joint. Axial fat-saturated spoiled gradient-echo MR image [TRITE/flip angle = 67/17/60”) shows a normal disc (arrowhead) and normal fibrocartilage (arrows) covering the clavicle (c) and manubrium (m). Note that the disc and fibrocartilage are the same signal intensity. This feature is consistent with their similar fibrocartilaginous histology. FIGURE
losing spondylitis, psoriasis, Reiter syndrome, gout, osteoarthritis, calcium pyrophosphate deposition disease, polymyalgia rheumatica, rheumatic fever, scleroderma, relapsing polychondritis, Behcet syndrome, and idiopathic self-limited arthritis. Rheumatoid arthritis of the SC joint, present in up
FIGURE 3. A 33-year-old male patient with a primary fibrosarcoma. (A) Tl-weighted (500, 20) (top) spin-echo and T2weighted (3,000, 93) (bottom) fast spin-echo sagittal images demonstrate a medial clavicular mass [urrows) with cortical destruction and soft tissue extension. (B) Tl-weighted (500,20) coronal image demonstrates involvement of the medial right clavicle (arrow) with lack of extension across the sternoclavicular joint into the manubrium. MR imaging is better than CT in the evaluation of joint invasion. Evaluation for tumor extension across joints is important for surgical planning. M, manubrium; C, left clavicle.
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B
51-year-old female with bone metastases from breast cancer. (A) Proton density (1,700, 20) axial image demonstrates focal infiltration of the manubrium (arrow) with normal bone marrow in both clavicles. (B] Fat-suppressed TZ-weighted (4,500, 80) axial fast spinecho image demonstrates that the marrow infiltration is hyperintense (arrow) with extension into the soft tissues anteriorly. The marrow fat in both clavicles suppresses normally, excluding trans-joint’ invasion. (C) Tl-weighted (700, 20) sagittal image demonstrates the expansile mass in the manubrium (short arrow) with cortical destruction and breakthrough and associated soft tissue extension. There is a second focal IO-mm lesion (long arrow) in the medial left clavicle with similar signal characteristics but without the cortical destruction or associated soft tissue mass. FIGURE 4.
to 41% of patients with the disease, causes joint effusion, uniform joint space loss, marginal erosions, pannus formation, and intra-articular disc destruction (1,8). The MR findings in patients with rheumatoid arthritis may be similar to those in patients with psoriasis and septic arthritis (Figure 6). All may demonstrate joint effusions, joint capsule distension, marrow edema, erosions, and unilateral involvement. Septic arthritis of the SC joint is uncommon, representing less than 10% of all cases of septic arthritis (Figure 7) (9). SC joint septic arthritis, associated with intravenous drug abuse, results from hematogenous spread, direct inoculation, or contiguous extension of a pathogen (9, 10). Since SC joint septic arthritis may cause only minor signs and symptoms, the diagnosis must always be considered in patients with unilateral SC joint pain; mediastinitis, superior vena cava syndrome, or septic shock can develop quickly (9). Imaging is important in the early diagnosis of SC joint septic arthritis since percutaneous as-
piration is often unsuccessful (1). The MR imaging findings, combined with the history, allow the radiologist to strongly suggest the diagnosis of septic arthritis. A previous case report of SC joint septic arthritis on MR demonstrated bone marrow edema and inflammation in the surrounding soft tissues (3).
C. SC Joint Surgery Iatrogenic causes of an abnormal SC joint include direct SC joint surgery as well as radical neck dissection, which indirectly involves the SC joint. Patients with postoperative changes in the SC joint may demonstrate findings indistinguishable from arthritis, including joint space narrowing, cortical irregularity, joint hypertrophy, and a joint effusion (Figure 8). Consequently, the relevant surgical history is imperative for accurate diagnosis. Following radical neck dissection for neck cancer the SC joint can become enlarged and look suspicious for tumor recurrence. In patients who have had
MARCH/APRIL
1997
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FIGURE 6. A 66-year-old male with known rheumatoid arthritis, new unilateral sternoclavicular joint pain, and a negative sternoclavicular joint aspiration. Proton density (2,000, 20) axial image of the left sternoclavicular joint demonstrates extensive pannus (black arrows), uniform joint space narrowing, and erosions (white arrow) with focal loss of low signal intensity cortex. M, manubrium; C, left clavicle.
B FIGURE 5. A 38-year-old female with bone metastases from breast cancer. (A) Tl-weighted (500, 11) and (B) T2weighted (2,200, 80) axial images demonstrate a focal lomm lesion (long arrows) in the left medial clavicular head, which is low signal intensity on both sequences. Although usually hyperintense, malignant lesions such as this bone metastases can have low signal intensity on T2-weighted images. No soft tissue mass or joint invasion is seen. This lesion could not be seen on the corresponding CT scan. If only a CT scan had been obtained, the cause of this patient’s SC joint pain would have gone undiscovered. There is a normal tiny amount of contralateral right sternoclavicular joint fluid (short arrow). the SC joint resected secondary to this suspicion, a mass of fibrous tissue surrounding and replacing the joint was found (11). SC joint periarticular fibrosis can develop 18 months after radical neck dissection (11). The abnormalities are thought to result secondary to nerve division at surgery creating altered biomechanical forces on the SC joint as well as denervation of the sensory supply to the joint (11).
D. SC Joint Trauma SC joint dislocations are rare, occurring anteriorly more commonly than posteriorly, in spite of the
stronger anterior SC ligament (12). Injury to the SC joint may result in ligamentous sprain without displacement, SC ligament but not costoclavicular ligament disruption with little deformity, or disruption
FIGURE 7. A 5%year-old male intravenous drug abuser with streptococcal septic arthritis of the right sternoclavicular joint. T2-weighted (2,000, 60) axial image demonstrates a large right sternoclavicular joint effusion (white arrow) with extension into the soft tissues anteriorly (black arrows), as well as cortical destruction [arrowheads) and joint space widening. The appropriate diagnosis can be made from the imaging findings and clinical history. M, manubrium; C, right clavicle.
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A 51-year-old female who underwent sternoclaviculsr joint surgery due to chronic dislocation. TZweighted (4,000,92) fat-suppressed fast spin-echo coronal image demonstrates a moderate sized joint effusion (long arrow), joint space narrowing, cortical irregularity (short arrow), and subjacent bone marrow edema in the right clavicle and manubrium. The patient had no past or present signs or symptoms of arthritis in her other joints. Her sternoclavicular joint was asymptomatic at a s-month follow-up without antibiotic therapy. Postoperative findings in the SC joint can be radiographically indistinguishable from inflammatory or infectious arthritis. M, manubrium; C, right clavicle. FIGURE 8.
of both ligaments with complete dislocation
(13). Posterior dislocation commonly results indirectly from trauma to the posterolateral clavicle (12) (Figure 9). Imaging is usually required for diagnosis. Posterior dislocation is important to diagnose since significant neurovascular injury, tracheal laceration, or pneumothorax can result (1).
FIGURE 9. Proton density (1,500, 22) axial image demonstrates a complete posterior dislocation of the right clavicle (long arrow). Imaging is essential in these cases to rule
out an associated mediastinal injury. The mediastinum is normal in this case. (Short arrow), manubrium.
A 67-year-old male with sternocostoclavicular hyperostosis and bilateral sternoclavicular joint pain. There was increased activity in both sternoclavicular joints on bone scan, which was stable for over 2 years. Proton density (2,000, 20) coronal image demonstrates ossification (black arrow) of the left costoclavicular ligament as well as heavy ossification of the first rib cartilage (white arrow). FIGURE 10.
E. Miscellaneous Conditions Ajjfecting the SC Joint Finally,
joint
miscellaneous
include
processes
the SC hyperostosis
affecting
sternocostoclavicular
(SCCH), Paget’s disease, condensing osteitis, primary and secondary hyperparathyroidism, and osteonecrosis. SCCH causes enlargement of the anterior upper ribs, sternum, and medical clavicles and is associated with adjacent soft tissue ossification (8,14). It is associated with certain skin diseases, such as palmoplantar pustulosis in slightly more than half the cases, and can be associated with peripheral or axial arthritis (14). The average age of onset is 47 years (14). The symptoms persist for many years; histologically nonspecific inflammatory change, fibrosis, and new bone formation are seen (14). Radiographically, the SC joint is involved in only 44% of patients whereas sternocostal involvement occurs in 48% (14). Radiographic findings include ossification of the costoclavicular ligament, fibro-osteitis of the costoclavicular ligament attachment site, and hyperostosis of the medial clavicle, anterior upper ribs, and sternum (14) (Figure 10). Advantages of MRI over CT include improved detection and delineation of abnormalities involving the bone marrow, cartilage, articular disc, extra artic-
MARCH/APRIL
MRI OF THE ABNORMAL
1997
ular soft tissues, and joint space, as well as its multiplanar capabilities, lack of radiation, and improved contrast resolution. Disadvantages of MR include decreased spatial resolution, worse motion artifact, longer examination times, and less sensitivity to cortical erosions and calcification/ossification. In conclusion, MR imaging can delineate the abnormal SC joint, allowing the radiologist to provide a limited differential diagnosis. Further study is needed to determine whether MR imaging will supplant CT as the primary imaging modality in evaluating the SC joint.
REFERENCES Yood RA, Goldenber DL. Sternoclavicular thritis Rheum 1980;23(2):232-239.
joint arthritis. Ar-
Cope R, Riddervold JO, Shore JL, Sistrom CL. Dislocations of the sternoclavieular joint: anatomic basis, etiologies, and radiologic diagnosis. J Orthoped Trauma 1991;5(3):379-384. Shanley DJ, Vassal0 CJ, Buckner AV. Sternoclavicular pyarthrosis demonstrated on bone scan correlation with CT and MRI. Clin Nucl Med 1991;10:786-787. Klein MA, Miro PA, Spreitzer AM, Carrera GF. MR imaging of the normal sternoclavicular joint: spectrum of findings. AJR 1995;165:391-393.
STERNOCLAVICULAR
JOINT
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5. Frank JA, Ling A, Patonas NJ, et al. Detection of malignant bone tumors: MR imaging vs scintigraphy. AJR 1990;155:10431048. 6. Bloem JL, Falke THM, Taminiau AHM, et al. Magnetic resonance imaging of primary malignant bone tumors. Radiographics 1985;5(6):853-886. 7. Bloem JL, Taminiau AHM, Eulderink F, Hermans J, Pauwels EKJ. Radiologic staging of primary bone sarcoma: MR imaging, scintigraphy, angiography, and CT correlated with pathologic examination. Radiology 1988:169:805-810. 8. Resnick D, Niwayama G. Diagnosis of Bone and Joint Disorders, 2nd ed. Philadelphia: W. B. Saunders, 1988, pp. 6742279. 9. Pollack MS. Staphlococcal mediastinitis due to sternoclavicular pyarthrosis: CT appearance. J Comput Assist Tomogr 1990;14[6):924-927. 10. Klein MA, Winalski CS. Wax MR, Piwnica-Worms DR. MR imaging of septic sacroiliitis. J Comput Assist Tomogr 1991; 15(1):126-132. 11. Lamb CEM. Sternoclavicular joint enlargement following block disection. Br J Surg 1976;63:488-492. 12. Cope R, Riddervold
HO. Posterior dislocation of the sternoclavicular joint: report of 2 cases, with emphasis on radiologic management and early diagnosis. Skeletal Radio1 1988;17: 247-250.
13. Ferrandez
L, Yubero J, Usabiaga J, No L, Martin F. Sternoclavicular dislocation: treatment and complications. Ital J Ortho Trauma 1988;14(3):349-355. 14. Saghafi M, Henderson MJ, Buchanan WW. Sternocostoclavicular hyperostosis. Sem Arthritis Rheum 1993:22(4):215-223.